Note: Descriptions are shown in the official language in which they were submitted.
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This applicat:ion is a divisional of application serial
number 272,882 filed March 1, 1977.
BACKGROIJND OF THE INVENTION
Covers for glass thermometers are disclosed by Govoni in
U.S. Patent No. 2,768,736. These covers are elongated one piece
-tubular members having closed ends adapted to Eit around the
temperature sensing end of the thermometer. The wall of the cover
is thin to allow rapid heating and heat transmission so that the
thermometer can quickly reach its maximum temperature. Electronic
1~ clinical thermometers are equipped with elongated probes having
temperature sensing elements. Disposable covers are releasably
mounted on -the probes so that the thermometer can be used with a
number of patients by merely replacing the cover. ~xamples of
this type of probe and cover are shown in U.S. Patents
Nos. 3,738,173 and 3,905,232. Tongret in U.S. Patent No.3,254,533
shows a disposable cover having an open end with an inwardly
directed flange positioned over a base on the probe. The closed
end of the probe has an aluminum tip for rapid transfer of heat
to the temperature sensing element of the probe~ Oudewaal in
U.S. Patent No. 3,822,593 discloses a disposable cover with a
flexible elastic tip. A sleeve structure is used to mount the
elastic tip on the end of the elongated tuhe. The elastic tip
is adapted to be stretched over the end of the temperature
sensing element of the probe. The tube has outwardly directed
projections locatable in a groove in the collar to latch the
cover on the probe. Another probe cover is disclosed by Naumann
in U.S. Patent No. 3,880,282. This probe has a one-piece tapered
hollow body having a small closed end. The wall thickness at
the closed end is thin to allow relatively rapid heat transfer
3~ throu~h the material of the closed end.
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SUM~RY OF THE I~ENTION
The invention is directed to a cover for an electronic
thermometer probe. The cover is a low cost disposable item and
is effective in allowiny rapid transfer of heat from a body to the
temperature sensing element of the probe. The temper~ture sensiny
probe has an elongated -tubular member carrying a probe tip. The
probe tip has a cone-shaped side wall surroundiny a tempera-ture
responsive element, such as a thermistor, The side wall has a
convex outside surface. A body is secured to the opposite end of
1~ the tubular member, providiny a passage for electrical conduc-tors
which are connected to the thermistor. ~ cylindrical collar
surrounds the body. A spring biases the collar over the body.
The collar has a head surrounding the tubular member. The head
has an outwardly directed rib or shoulder. The shoulder forms
part of a coacting releasable lock or latch s-tructure which re-
leasably holds the cover on the probe. The cover is a dlsposable
item having an elastic body or tube attached to a closed end member
forming a cover chamber. The tubular probe member and tip are
located in the cover chamber. The cover body has an open end
having an annular bead surrounding the head to hold the body in
assembled rela~ion with the tubular probe member and tip. The
head forms an elastic second part of the coacting releasable latch
structure that holds the cover on the probe. The closed end
member has a cone-shaped thermal window section and a thicker
blunt closed end or ront wall. The thermal window section has a
thin flexible annular wall. The flexible wall is deformed or
~lexed into sur~ace engagemenk with the convex shape of the side
wall of the probe tip so that heat is readily transferred through
said thermal window section to the probe tip and temperature
responsive element carried by the probe tip.
The cover has an elastic tubular body of plastic having
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i a yenerally cylindrical side wall surrounding a chaI~ber. A close-l
end member is s~cured to one end of the tubular body. The otneL
end of -the body is open and has an annular bead. The end member
has a thermal window section formed by a thin flexible annular
wall to permit rapid heat transfe.r through the thermal ~7indow
section~ The window section is yenerally cone-shaped and pre-
ferably has a wall thickness in the range of .006 to .009 inch
(.15 to .23 mm). The inside sur~ace of the thermal windo~J section
tapers in a forward direction toward the closed end.
An object of the invention is to provide a low cost dis-
posable cover or sheath for a temperature sensing probe that i5
safe, sturdy and reliable in use, can be sterilized, and is
easily assembled and release~ from the probe. Another object of
the invention is to provide a probe cover with an annular window
section that can be located in deformed surface engagement with a
probe tip having a temperature sensing element. A further object
of the invention is to provide a probe cover and probe combination
with releasable latch structure that ~ill hold the cover in
operative relationship with the probe tip and can be readily re-
2~ leased from the probe. Another object o~ the invention is to
provide a coacting latch structure between a probe and probe cover
that re~uires an external positive force to separate the cover
from the probe~ An additional object of the invention is to pro-
vide a cover for a temperature sensing probe that is ecologically
conservative as it is made with a minimum of material,by automatic
machinery. Yet another object of the invention is to provide a
cover for a temperature sensing probe that has a flexible body
that can be easily deformed by the lips, gums or teeth of a
patient. ~ still further object of the invention is to provide a
~ cover for a temperature sensing probe that has self ejecting
or propelling behavior from the probe when released from the head.
These and additional objects, advantages and features of the
temperature sensing probe and cover for the probe are set forth in
the following descrip-tion and drawings.
IN THE DRAWINGS:
Eligure 1 is a side elevational view of a temperature
sensing probe and disposable cover thereEor of the invention;
Figure 2 is a sectional view taken along line 2-2 of
Figure l;
Figure 3 is an enlarged sectional view of the temperature
sensing end of the probe and cover o~ Figure l;
Figure 4 is a sectional view taken along line 4-4 of
Figure 3;
Figure 5 is an enlarged sectional view of the coacting
releasable lock structure of the probe and cover;
Figure ~ is a sectional view taken alony line 6-6 of
Figure l;
Figure 7 is a side elevational view of the disposable
cover of the invention;
Figure 8 is a sectional view taken along line 8-8 of
Figure 7;
Figure 9 is an enlarged sectional view of the closed end
of Figure 7;
Figure 10 is a sectional view taken along line 10-10 of
P'igure 9;
Fiyure 11 is an enlarged end view of the open end of
Figure 7; and
Figure 12 is an enlarged sectional view taken along line
12-12 G-f Figure 8.
DESCRIPTION OF PRP'F~RR~D EMBODIMENT
3~ Referring to the drawing, there is shown in Figures 1 an~
2 a temperature sensing probe assembly indicated generally at 20
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1 equipped with a ~isposable cover or sheath 21. The probe 20 is
part of an electronic thermometer used orally or rectally by nurses,
nurses aids, paramedics, physicians and veterinarians to read the
temperatures of humans and animals. An example of an electronic
thermometer having a digital readout is disclosed by Kauffeld and
Holst in U.S. Patent No. 3,872,726.
Probe 20 has a cylindrical collar or sleeve 22 surrounding
an elongated cylindrical chamber 23. A head 24 projects for-
wardly from the collar 22. As shown in Figure 5, the forward end
of head 24 has a cone-shaped converging nose 26 providing a tapered
guide surface for the open end of cover 21. An outwardly directed
annular shoulder or rib 27 is located rearwardly of the nose 26 and
forms an annular recess or groove 28 with a shoulder 29 on the
forward end of collar 22. Head 24 has a longitudinal axial passage
31 slidaly accommodating a tubular member 32. Member 32 is made
of rigid material, as stainless steel tubing.
An elongated cylindrical bocly 33 is located in chamber 23.
Body 33 has a lon~itudinal passage 34 with a portion accommodating
one end of tube 32 to connect the tube to body 33. Electrical
conductors 36, as wires, are located in passage 34 and the passage
of tube 32 to electrically couple a temperature or heat sensing
element 48, as a thermistor, to the elec-tronic circuit of the
thermometer. The forward part of body 33 has an enlarged out-
wardly directed annular flange 37 and a front end carrying an
annula~ washer or cushioning member 3~. Flange 37 is engaged by
a coil spring 39 concentrically positioned abou-t body 33. The
spring 3g en~ages an annular cap 41. Cap 41 has a center hole 42
which permits body 33 to project through cap 41. Collar 22 has an
outwardly directed annular ring 43 having an axial flange 43A
surroundi.ng the cap 41~ The inside of flange 43A has an inclined
or tapered annular surface which cooperates with the outer peri-
pheral edge of cap 41 to hold the cap 41 in firm assembled engage-
1 ment with ring 43. Preferably, the collar 22 and ring 43 are
made of a one-piece plastic material which is rigid but which has
sufficient elasticity to perrnit flange 43A to stretch so that
the cap 41 can be removed ~rom ring 43. Ring 43 has a pair of
holes 44, shown in Figures 2 and 6, which are used to accommodate
a tool having fi.ngers which apply a longitudinal force to cap 41
to remove the cap from ring 43.
The outer end of body 33 is closed with a cup-shaped cap
45. Cap 45 has a side opening 45A providing an outlet for the con-
ductors 36. The cap 45 is also a hand engaging member used inconjunctio~ with fingers in contact with ring ~3 to remove the
cover 21 ~rom the probe 20.
Referring to Figures 2 and 3, tube 32 extends the length
of cover 21 and is connected at its forward or right end to a
coupling or probe insulator 46 of electrically and thermally in-
sulative materia]., as a plastic such as polycarbonate. Coupling
46 has a longitudinal passage 47 for accommodating portions of
conductors 36 that are connected to the temperature sensing
element 48. A probe tip indicated generally at 49 is mounted on
the forward end of coupling 46. Tip 49 has a generally flat,
circular ~orward or closed end 51 having an inside surface in
engagement with the temperature sensing element 48. Element 48 is
secured to end 51 with a suitable material, such as solder or
. the like. End 51 is integral with a cone-shaped side wall 52.
: Side wall 52 terminates with an inwardly directed ~lange 53
which fits into an annular groove 54 in coupling 46 to secure tip
~9 to coupling 46. The side wall 52 has an outside an.nul.ar surface
or face 52~ having an out~7ardly curved or convex shape For
- e~ample, the outer surace 52A of wall 52 has a 0.5 inch radius
(12.7mm) normal to the longitudinal axis of the cone. Tip 49 is
made o~ heat transmitting materi.al, such as silver or a li~e me~al.
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eferring to Figures 7~ the probe cover or sheath ~l has
an elongated hollow body or tube 56. Body 56 is a one-piece
plastic tubular member having a thin cylindrical side wall and
can be ma~e from polypropylene, polye-thylene and like plastics.
Body 56 is a flexible and elastic plastic and has a thin cylin-
drical wall that can be longitudinally and circumEerentially
stre-tched. The plas-tic is smooth and compatible with body tissue
and resistant to body fluids. Body 56 has an open end 57 and an
elongated linear passage or chamber 55. A tip or closed end
1~ member 58 is mounted on the forward end of body 56. Member 58 has
a cylindrical open end section or tubular section 59 surrounded
by the forward end 56A of body 56 and a longitudinal chamber 60.
Section 59 has a wall thic~ness of about .025 to .035 inch or
.6 to .9 mm~ A pair of annular ribs 59A project outwardly from
the outsid~ surface of section 59. End section 59 joins a middle
section 61 having an annular shoulder 62 and a forwaxd tapered
surface 63. Shoulder 62 provides a rectal insertion indicia or
line indicating the proper rectal penetration position of the
cover. The forward end of body 56 abuts against shoulder 62. As
~ shown in Figures 3 and 8, the outside diameter of sec~ion 59
is larger than the inside diameter of body 56 so that end 56A
is enlarged or stretched over section 59. The end 56A is in
tight annular surface engagement with the outside surface of
section 59 and its ribs 59A~ A heat seal or fuse 6~ permanently
bonds and seals the end 56A to section 59 so.end member 58
cannot be removed from body 56 and prevents body fluids from
flowing into cover chamber 55.
Referring to Figures 8 and 9, end member 58 has a generally
flat transverss or blunt closed end or front wall 66 integral
with an annular cone-shaped wall section 67. Wall 66 has a
diameter of about half the diameter of the side wall
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1 56 of cover 21 and as best seen in Fig. 9, the blunt end 66 is
appreciably thicker than the cone-shaped windo~ section 67. Section
67 has an inside cone-shaped surface 68. Surface 68 is straight Gr
linear and convercJes in a forward direction -toward end 66. Pre-
ferably, surface 68 is inclined at an angle of 16 rela-tive to the
longitudinal axis of the chamber 60. This angle can range between
12 and 20. The wall section 67 is relatively thin as compared
to the -thickness of section 59. Wall section 67 is elastic and
flexible so that it can be stretched, distended o-. expanded over
1~ the probe tip 49. The material of section 67 has characteris-tics
such that it does not deform or stretch beyond its elastic limit
when the cover is in assembled relation with the probe. The
elastic contracting force of the plastic of section 67 holds the
inside surface 68 in firm and full surface engagement with the
side wall 52A of the probe tip ~9. Preferably, wall sectlon 67
has a thickness of between .~06 and .009 inch, or .15 and .23 mm.
Section 67 has a wall thickness o~ about one-fourth the thickness
of the side wall 59 of end member 58. The cone-shaped wall
section 67 fo~ns an annular thermal window which is relatively
~O thin to permit con-trolled and efficient heat trans~er between
the outside environment and the inside of the chamber 60. The
thermal window is indicated at 69 in Figures 2, ~ and 9.
As shown in Figures 7, 8, 11 and 12, the end of body 56
surrounding the opening leading to the body passage 55 has an
annular bead indicated generally at 71. The bead 71 is con-
tinuous and has an inwardly directed rib or flange 72 and an
outwardly directed rib or ~lange 73. The bead 71 functions to
rein~orce the end o~ body 56 and acts as an elastic ring or
garter that holds the cover in assembled relation ~ith the probe.
Bead 71 is part o~ the coacting latch structure that holds the
cover 21 on probe 20.
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1 In use, probe 20 is coupled ~ia the electric line or cord
36 to the electronic thermometer an~ is a permanent and reusabl~
part of -the thenmometer. Cover 21 is a disposable item that has
a single use In other words, after the temperature o-f a patient
is monitored by the electronic tnermometer, the cover 21 is
ejected Erom the probe 20 and a new cover is mounted on the probe
for use with another patient.
A new cover is placed on the probe tube 32 by inserting
the -tube 32 into the cover passage 55 through the open end 57.
The probe is moved into the cover 20 until the probe tip 49 is in
full surface engagement with the inside surface 68 of the
annular cone-shaped wall 67 and the annular bead 71 is located
in the annular groove 28 behind shoulder 27. The collar 32 is
moved toward the tip 49 to force -the annular bead 71 along nose
26 to the groove 28. The body 56 has sufficient strength so
that the bead 71 rides up on the nose ~6 and circumferentially
expands until the bead 71 is located in the groove 28. As soon
as the bead 71 passes over the shoulder 27, it contracts so
that the inner annular rib 72 is in annular engagement wi-th the
shoulder 27. When the cover 21 is fully mounted on the probe 20,
the cone-shaped outer wall 52A of the pro~e tip 49 is in full
and firm surface engagement with the inside cone-shaped surface
68 of the wall section 67. Wall section 67 is slightly deformed
outwardly into a convex shape as the cover 21 is pulled over
the probe tip 49 to deform the relativel~ thin wall SectiQn 67.
This insures a uniform annular surface engagement over the
length of the surface 52A of the probe tip 49 so that there is a
controlled an efficient transfer of heat from the outside environ-
ment to the probe tip 49. Spring 39 acting on cap ~1 and body 33
yieldably pulls cover 21 into engagement with the tip 49 to
ma~in-tain the ful]., firm surface engagemen-t between the surfaces
3 52~ and 68, The elas-tic side wall 56 of cover 21 also functions
as a biasing means or spring to bias the flexible ~Jall 67 of the
thermal window section 69 into full surface engagement with the
conve~ shaped side wall 52A of tip 49.
Cover 21 is released and removed from the probe by applying
a compressive Eorce to spring 39. This is accomplished by
gripping ring ~3 wi-th the first two fingers. The base of the
thumb is placed against the end of cap 45. A squeezing force
will compress spring 39 and provide relative movement collar 22
10 and tube 32. Thus, the head 24 and probe tip 49 are moved in
opposite longitudinal directions. The relative movement
between head 24 and probe tip 49 will elongate or stretch the
elastic body 56 until sufficient force is developed to expand
the annular bead 71 so that it will slip over the shoulder 27.
Once the annular bead 71 is free of shoulder 27 r the body 56
will re-turn to its non-stretched or original position. This
provides the cover 21 with a reversing thrust or force so that
it will propel itself from the probe tube 32. The operator
can direct the cover 21 to an appropriate disposal container
~o without touching or handling the used cover.
While there has been shown and described a preferred
embodiment of the temperature sensing probe and disposable cover
for the probe, it is understood that changes in size, shape,
structure and materials can be made by those skilled in the art
without departing from the invention.
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